I've decided to release a script that I mainly wrote for my own missions but since I was told that it could be interesting for others, I decided to release it.
The script is the FHQ TaskTracker, as the name implies, it's used to handle and maintain mission tasks and briefings. It can automatically keep track of task states, briefing text, dynamically add both tasks and briefings, and distribute them over the network to clients that join in progress. Also supports the use of parented tasks, and is compatible to both ArmA 2 and Arma 3 (it will take care to add the tasks and briefing entries in the correct order as specified)
The archive also contains documentation on it's use.
New version available:
V1.1 - Adds Arma 3 notification support, as well as a demo mission to explain the use of the script in a practical example
V2.0 - Complete rewrite. Adds support for JIP into disabled units/respawn
V2.1 - Fixed a bug in task creation notifications
V2.2 - Fixed a bug in task creation notification (for real this time). Thanks to FortuN for pointing this out.